Momentary contact push switch



July 18, 1939. F; c. DEj- EAME MOMENTARY CONTACT pfisa SWITCH.

Filed July 29; 1936 P o m e V m.

Frank C. De Reamer- His Attorney.

Patented July 18, 1939 UNITED STATES PATENT OFFICE Frank C. De Reamer,Bridgeport, Coma, assignor to General Electric Company, a corporation ofNew York Application July 29, 1936, Serial No. 93,237

2 Claims.

The present invention relates to push button operated electric switches.

The object of my invention is to provide animproved construction andarrangement in switches of this type, and, for a consideration of what Ibelieve to be novel and my invention, attention is directed to theaccompanying description and the claims appended thereto.

In the accompanying drawing, Fig. 1 is a side elevation of an electricswitch embodying my invention; Fig. 2 .is a sectional elevation taken online 2--2 of Fig. 1; Fig. 3 is an exploded view of the switch; Fig. 4 isa bottom plan view of the switch; Fig. 5 is a sectional elevation of amodiflcation; and Fig. 6 is an enlarged view showing the manner ofassembling the terminal.

Referring to the drawing, I have shown my invention applied to a switchhaving a housing I of molded insulating material having bosses 2 atopposite sides thereof. In the upper faces of the bosses are recesses 2for receiving terminals 4 which comprise V-shaped metal strips with thesides 5 of the V pressed tightly together. At the junction of the sidesof the V the terminals are provided with openings through which extendthe bored ends 6 of stranded line conductors I. With this arrangementthe bared ends of the conductors are fanned out and forced into firmelectrical contact with the sides 5 of the terminals when the sides ofthe terminals are clamped together. From another aspect, the terminals 4can be considered as a strip having one end 5 folded over the other,there being an opening in the strip intermediate its ends through whichthe bored end of a conductor is inserted and held in place by pressingthe ends of the strip togetheni. -.-The terminals are held in therecesses 3 by projections I on the terminals which fit into depressions9 in the recesses. The

upper end of the housing is closed by a sheet or member ID of insulatingmaterial which is provided with ears H extending over the bosses 2. Whenthe member III is secured to the top of the housing, the ears Ii clampthe terminals securely in the recesses 3 and also increase the clampingeifect of the sides of the terminals on the bared ends of the conductorsthereby providing a connection between the terminals and the conductorswhich does not require soldering. The member I0 is secured to the top ofthe housing by a metal plate 12 having tangs l3 which are bent over abead M at the top of the housing. As shown in Figs. 1 and 4, tangs l3engage the sides of the bosses 2 and locate the metal plate I? on top ofthe housing. The tangs I 3 also exat the upper end of the reducedportion tend on either side of. the ears II and thereby prevent turningof the member ID with respect to the housing. The conductors I aresupported by an arm We on the plate 12. The conductors are first drawntightly against the switch housing and are secured tothe arm l2a by earsl2b which are folded over the conductors. The metal plate I2 is securedto the lower end of a. threaded sleeve l by spun-over portions IS. Theswitch may be mounted by extending the sleeve through a support and byclamping the support between nuts I! threaded on the sleeve.

In the sleeve I5 is apush button which com-' prises a .drawn tubularmetal shell IS, the closed end of the shell projecting beyond the sleevel5 where it may be engaged by the operator, and the tubular body portionof the shell being .slidable in the sleeve. Within the shell I8 is anoperating rod or spindle 19 which is secured therein by a washer 2iwedged into the shell. The operating rod has a head 2| which provides ashoulder 22 co-operating with the washer to hold the operating rod inplace. The lower end of the operating rod is guided in an opening 23 inthe member Hi. There is sufllcient clearance between the washer and theoperating rod, and between the head 2! of the operating rod and the endof the shell It, so that the operating rod may have a limited angularmovement in the shell, or, viewed from another aspect, the operating rodis free to swivel in the push button. The swiveling of the operating rodprevents binding of the operating rod in the guiding opening 23 in casethe member II is assembled so that this opening is not in exactalignment with the operating rod. The operating rod l9 projects belowthe member ID and the projecting end is provided with a reduced portion24 on which is loosely carried a washer 25 of insulating material. Thewasher 25 is held in place by turning over the end oi the operating rodto form a flange so that the washer fits loosely between the flange andthe shoulcie: Around the periphery of the washer is a metal rim 26 whichserves as a bridging contact which co-operates with the inner ends ofterminals 4 to complete an electric circuit between the terminals.

The push button is biased to the outer position shown in Fig. 2 by acoil spring 21 which is arranged around the operating rod and betweenthe member ID and the washer 20. The spring biases the push buttonoutwardly so that the metal rim 2B is normally held against theterminals 4 to complete a circuit between the terminals. There issuiilcient clearance between the washer 2' and the groove 24 so that themetal rim It can align itself with the terminals and thereby provideuniiorm contact with the terminals. The circuit between the terminalsisbroken by pushing the push button inward.

The switch shown in Figs. .1 to 4 inclusive is I 01' the type in whichthe circuit through the switch is normally closed. In Fig. 5 is shown amodification or the switch in which the circuit through the switch isnormally open.

The construction of the switch shown in Pig. 5 is identical with theswitch shown in Figs. 1 to 4 inclusive except for the construction ofthe terminals, the stationary contacts, and the push button and theidentical parts are indicated by the same reference numerals. Theterminals comprise angular metal strips II. the upper ends of which atwithin the depressions l, andthe. lower ends of which serve as solderlugs which are soldered to the bared ends i o! the line conductors 'l.Theupperendsoi thestripstlaresecuredto contacts Ii which ilt in groovesin the switch 4 housing. At the bottom the contacts are provided withastepped portion 38 which is arranged to cooperate with the contact IIon the lower end of the operating rod Ii. Between the head II of theoperating rod and the end of the shell II is a coil spring 84. Thisspring normally holds the shoulder 22 of the operating rod against thewasher II, but permits the operating rod to move upwardly in the pushbutton when the resistance oii'ered to further movement of the operatingrod exceeds the tension of the spring. The push button is normally heldin the position illustrated by the coil spring 21 which isarrangedbetween the member II and the washer ll.

In this position the contact it is held against the underside oi themember II and the circuit between'the contacts ii is open. when the pushbutton is pushed inward the contact I. is moved into engagement with thestepped portions 33 of the contacts ll, thereby completing the circuitbetween the contacts. During the initial movement 5 of the push buttonthe spring 34 is not compressed and the operating rod occupies theposition in the push button illustrated. As soon as the contact pressurebetween the contacts ll and 33 exceeds the tension 0! the spring 84 theoperat- 10 mg rod moves upwardly with respect to the push button. Thespring 8|. therefore. provides a cushion between the operating rod andthe push button, which limits the contact pressure between the contactsI. and 38.

whatlclaimasnewanddesiretosecureby 1 LettersPatent of the United Statesis:

1. In an electric switch, a housing of insulating material, a sleevesecured to said housing. a

member of insulating material clamped between a said sleeve and saidhousing. recesses in said housing adjacent said member. terminalsclamped in said'recess by said member. and a spindle uided in saidsleeve and said member of insulating material carrying contactscooperating with u said terminals.

2. In an electric switch, a housing oi insulating material, a sleevesecured to said housing. a member of insulating material clamped betweensaid sleeve and said housing, recesses in said so housing adjacent saidmember, terminals clamped in said recess and projecting within thehousing, the upper sides thereof being in contact with the under side ofsaid member, and a spindle guided in said sleeve carrying contacts'belowsaid terniig;

nals movable upward into engagement with the under sides or theterminals.

FRANK C. DE mum.

